- CSF CXCL13 levels was significantly higher in RRMS and PPMS than in the control group; - in the stable phase of disease, CSF CXCL13 levels in RRMS and PPMS patients demonstrated no significant difference; - patient age and CXCL13 levels in the CSF in all groups demonstrated no significant correlation;. The gene discussed is CXCL13; the disease is primary progressive multiple sclerosis.